Downtown London Ontario Apartment 2ply Flat Roof System Re-Roof

Hi everyone, this week we were in downtown London, Ontario. Our team was called in to a multi tenant building to have their flat roof system re-rooofed. When we first went for our site inspection we noted that the roof was well past it’s lifetime, the client had reported the roof was having a lot of leaks, and in the first section of the video you can see that some repairs were undertaken on the roof, but without much success. Legacy Flat Roofing was called in as the stop gap solutions weren’t working.

We presented the client with a few options – a full tear out down to the roof deck and put a new system in, or install a new substrate over the top of the existing system, and then install a new roof. The benefit to the first option is that we can ensure no moisture is in the flat roof before installing a new system. We gave price options for both, along with our recommendations and presented them to the client, who decided to go with the section option, which is the layover option.

We were ok with the second option as the roof was nice and dry, and we could see that it would be a cost effective, and still protect the building envelope.

There’s a few details on this project, some stairs, some siding, a vent, and a drain to work around, but nothing we haven’t seen or faced before! However those details will slow the project down a little as the client didn’t have the budget to remove the stairs, so we need to take our time to work around those details to make sure the flat roof is as effective as possible.

Laying over a roof system this old, we wanted to create a separation layer by using a peel and stick base sheet that is a little thicker and sturdier than the regular waterproof peel and stick membrane we use. This one is peel and stick, and the seams are welded. This creates a very strong waterproof layer with which to build on. Any parts of the roof that we found to be soft or not as strong we screwed down sopraboard panels, another name for these is a recovery or separation board, we fastened them to the old deck to create a strong foundation.

Getting the membrane under the stairs was a delicate task, we had to jack up the feet of the stairs to install the membrane under the feet of the steps. When putting the feet back down it’s important to use some foam insulation boards before the weight touches the membrane, as this distributes the weight and avoids any risk of puncturing the membrane.

Once the membrane is down the drains are set in place and all the detail work is out of the way, we install the base sheet, heat weld the seams, and then install the metal flashing around the detail areas. We’re so excited with the way this came out, a real night and day difference with the look of the roof, and of course the effectiveness of this new 2ply system.

If you live in SouthWestern Ontario and you need flat roof repairs, or a brand new flat roof system we’d love to hear from you.